This invention relates to a knitting machine, and more particularly to a method and an apparatus for providing patterning instructions in such a machine.
In a knitting machine, particularly a hard-operated knitting machine having an electromechanical needle selection mechanism, a program reading device is provided for reading design instructions on a design paper or program carrier to produce electric signals for controlling the needle selection mechanism. Typically the signals thus produced are stored in a temporary electronic storage memory and recalled from memory in response to movement of the machine carriage relative to knitting needles in the needle bed. The signals thus recalled from memory are then applied to the needle selection mechanism to cause the needles to be selected in accordance with the original design instructions. In the course of knitting a fabric, typically a predetermined unit number of signals will be required to be repetitively recalled from storage so that a unit design may be repetitively produced in the horizontal direction in the fabric.
A conventional design paper has rectangles thereon arranged in rows and columns and the design instructions are placed on the design paper by selectively darkening the rectangles. The design paper typically includes design instructions constituting a unit design, which comprise a predetermined unit number of design instructions in a row. The unit number, however, is required to be selectively variable according to the particular design to be knitted. It is, therefore, necessary for a program reading device to be provided having means for specifying or determining the unit number for control of the memory.
A suitable program reading device is disclosed in U.S. patent application No. 737,433, titled "A Knitting Machine Coupled With the Program Reading Device", filed on Nov. 1, 1976. In that device the program carrier itself includes an instruction mark for specifying the unit number and the mark is detected by an electronic reading means prior to the reading of the design instructions on the program carrier. Thus, each program carrier has the appropriate unit number fixedly specified on it by a mark.
For reasons of economy, however, a single program carrier may include several unit designs not all having the same unit number. Additionally, it is sometimes desirable to reproduce repetitively only part of a unit design on a design paper in the horizontal direction in a fabric. To provide for such cases, the unit number must be specifiable independently of the program carrier itself.